New Twist on Phase-Shedding

An “eco mode” method for managing parallel arrays of power modules in an intermediate-bus power-distribution system optimizes efficiency across loads better than conventional approaches commonly used to boost power supply efficiency, such as pulse skipping or the use of low-power “standby supplies.”

The technique is similar to phase shedding, which is often used to optimize light-load performance for multi-phase buck regulators, which are used to provide low-voltage, high-current power to microprocessors. In this case, however, the implementation is different as the “phases” are actually independent power components and the technique is employed at the intermediate bus stage rather than the point of load.

The “eco mode” method makes it possible to eliminate not just the losses in the switching FETs when “phases” are shed, but also the losses in entire modules when the individual components are turned off.